This is the astronomical telescope known as the "Model Otsu," the first 1-inch telescope produced by GOTO. Released in 1927, just four months after the company's founding, it was priced at 30 yen. A few months later, the all-metal 1-inch "Model Ko " telescope, featuring a metal main tube, was released for 40 yen. At the time, the starting monthly salary for a university graduate ranged from 50 to 70 yen, and a cup of coffee cost 10 to 15 sen. Astronomical telescopes were extremely expensive—costing 550 yen for a Nippon Kogaku model, 255 yen for an entry-level British model, and 780 yen for a Carl Zeiss model—resulting in Nippon Kogaku selling an average of only one unit per year. Seizo developed this product at a drastically low, popular price point so that schools could afford to purchase it. Priced at 30 yen based on a nationwide survey sent to schools, this telescope became widely beloved under the name "1-inch Telescope."
*”Ko” and “Otsu” are traditional Japanese terms equivalent to “A” and “B”. ＊Photo: The existing 1-inch telescope, photographed on the rooftop of the Fuchu Head Office.

In 1930, GOTO exhibited its "Precision Orrery" at the Sea and Sky Exposition held in Ikenohata Park, Ueno, Tokyo. Praised as "an extraordinarily exquisite work rarely seen among Japanese creations," the device was awarded a Gold Medal by the exposition committee. For our newly established company, this presentation served as an invaluable opportunity to demonstrate our product development capabilities and technical expertise. Furthermore, Dr. Issei Yamamoto of Kyoto Imperial University named it the "Japanese-Made Planetarium," pointing out that the orrery operated on the exact same principles as the planetary gearing system of a planetarium. This intriguing episode subtly foreshadowed our company's future challenge of manufacturing the first domestic planetarium.
Photo: The Precision Orrery and Dr. Issei Yamamoto

As the house in Sangenjaya became too cramped, Seizo found a suitable plot of land in Tsurumaki and relocated the business. With a team of approximately 40 employees, the facility handled the entire production process of telescopes under one roof. At the center of the site, an observatory with a 3-meter dome was established, creating a system capable of manufacturing telescopes with an aperture of 10 cm.

The factory was equipped with dedicated facilities for metalworking, finishing, lens polishing, assembly, and an optics laboratory. At the time, the company employed approximately 30 workers, and throughout the wartime, and post-war periods, numerous telescopes were produced at this site.